Gas-containing structures such as water playthings and car tires conventionally employ a valve for injecting and evacuating a gas, particularly a one-way valve, which allows the flow of a gas in only one direction, but no flow in the opposite direction. Through this type of valve, the air is blown into such a structure or a gas is inflated by means of a gas-filled inflator such as an air pump. On the other hand, the gas-containing structure releases the gas by opening a valve.
For example, Japanese Unexamined Patent Publication No. 8-61534 discloses an air vent valve for air removal from the tire. In this invention, the screwing of the air vent valve into a tire valve will open the valve, thereby causing the filled air to push up the valve element against an energizing force of a spring and providing an air vent space for air release. Subsequently, the completion of air release with its pressure reduction at a predetermined level will be followed by spring restoration, whose force exceeds the released gas pressure to pull back the valve element to fill the air vent space.
Meanwhile, another Japanese Unexamined Patent Publication No. 10-213243 discloses an air valve device with a flat surface to be mounted on a tire for air inflation. In this invention, a valve body is placed under the wheel surface with a flat cover being screwed therein, to improve the tire valve appearance and prevent the valve from causing failure by coming in contact with such objects as curbs. For air inflation, the flat cover is removed and a coupler including an extensible presser pin is screwed to the valve body. With being connected to an air nozzle of an air compressor, the coupler pushes the extensible presser pin against a valve opening pin to fill the air.    1. Japanese Unexamined Patent Publication No. 8-61534    2. Japanese Unexamined Patent Publication No. 10-213243